Inactive Subscribers are Still Valuable Customers

But what about those other people? You know, the ones who don’t even open your emails? They signed up for your list, but you’re not really sure if they care. Why are they still subscribed? Should you remove them from your list? What’s the deal with inactive subscribers?

Believe it or not, there’s more to the story than just opens and clicks. Your inactive subscribers might not be actively engaging with your email, but that doesn’t necessarily mean that they haven’t noticed your message or skimmed through your subject lines. Even without a single email being opened, your brand can still make billboard-like impressions on subscribers from the inbox.

In order to understand the true value of an inactive subscriber, you have to analyze revenue. So, that’s what we did. Luckily for us, MailChimp sends email on behalf of hundreds of thousands of retailers and merchants worldwide, so there’s no shortage of purchase data to sift through.

After crunching all the numbers, we’ve got some great news—it turns out that 1 inactive subscriber is worth 32% of an active subscriber. That’s a lot of revenue! We also learned that inactive subscribers purchase more frequently and are less likely to churn than customers who aren’t subscribed to your email list. This isn’t what we and a lot of other folks have said over the years, so allow us to explain a little more.

Learning from 6.6 billion sends

That’s what we analyzed, and those sends included 60 million e-commerce purchases and 40 million email addresses from retailers that use our e-commerce features for list segmentation and automation. We considered an email address "active" if it had opened or clicked in the previous 6 months. If an address had been sent campaigns but not opened any of them, we considered it "inactive." On average, 61% of retailers’ recipients in 2015 were active.

We then determined if each purchase from these retailers had been made by an active, inactive, or non-subscribed customer. We wanted to know how each customer type would differ on key retail metrics, so we focused on calculating the average purchase frequency, retention rate, and order value.

As it turns out, both active and inactive subscribers outperform non-subscribed customers in every way. Subscribers order at least 25% more frequently, and when they do, they spend at least 6% more than non-subscribers. Most importantly, they are much more likely to return. Inactive subscribers are 26% more likely to make a follow-up purchase than non-subscribers, and active subscribers were actually 38% more likely to come back.

At a higher level, it’s important to note how much revenue comes from each type of customer. On average in 2015, 56% of revenue came from customers who were not subscribed before ordering, 37% came from active subscribers, and 7% came from inactive subscribers. If we only consider revenue from subscribers, 84% came from active subscribers and 16% came from inactive subscribers. Overall, an average of 45% of a retailers’ revenue comes from individuals who were subscribed.

As we noted earlier, 61% of recent recipients are active, but it appears that they account for 84% of subscriber revenue. We can use the following calculation to compare the revenue per subscriber from the active and inactive segments of a list:

When we average this value across retailers, we found that an inactive subscriber was worth 32% of an active subscriber. We performed a similar calculation and found that inactive subscribers are also 32% as likely to convert as active subscribers. These percentages line up because, as we showed earlier, inactive and active subscribers spend about the same amount on an order. Active subscribers end up being worth more because they churn a lot less and keep spending money.

So, how should you treat your inactives?

Good question. Inactive subscribers might not engage with your email, but they still generate a lot of revenue. After all, they churn less, buy more frequently, and spend more than non-subscribers. Here are a few recommendations:

Don’t prune them from your list, though. This is the opposite of what we and many other marketing companies have said over the years, but the data backs it up: An inactive subscriber is a better customer than a non-subscriber.

Encourage all of your customers to join your list. A customer’s inbox is valuable marketing real estate, even if they don’t read your campaigns. Connect your store to MailChimp to automatically capture new subscribers as they make a purchase, and consider offering list-exclusive giveaways, contests, or coupons to your customers to help drive signups.

There you have it—inactive subscribers can still be key contributors towards your bottom line. If you sell things for a living, it’s important to look beyond the open rate and pay closer attention to the purchase behavior of your customers. Fortunately, MailChimp makes it easy to track your purchase data, so you can act on it. Remember: it’s great if someone actively engages with your email campaigns, but it’s even more important that they actively engage with your store.

Since MailChimp uses strong double opt-in and algorithms to detect import of risky data, MailChimp clients should never have poor quality inactive data – which means the inactive data is very valuable.

Hey Brett, I head the deliverability team for MailChimp, and you’re completely right! If you’re not making it to the inbox, you may want to consider some remediation tactics up to and including getting rid of those inactive addresses temporarily or permanently. This is because ISPs like Gmail will negatively score your emails based on whether previous sends were automatically or manually moved to the spam folder.

Now, spam filters are notorious black boxes, but from what I understand, lack of pruning is probably not what got your emails going to the spam folder in the first place. For that, you want to…

– Look at your abuse complaints
– Make sure you’re removing bounces and unsubs
– Review your list collection policies
– Introspect on what kind of emails your subscribers are expecting to get
– Analyze how users can get off your list other than sending your content to the spam folder

As long as your emails are going to the inbox and you have good list collection practices, inactive addresses pose a very low risk for broader deliverability issues. If you aren’t making it to the inbox, those inactive addresses may be hurting your deliverability, but they aren’t necessarily causing the issue. Hope this helps!

Hey Elizabeth,
Unfortunately, I do not have any specific examples of good content. In reality, what works for your subscribers will be different from others. The key is that inactive subscribers really only see your subject, so it is possible to learn a lot by split testing subject lines on segments of inactive subscribers. Good luck!

What if you are not an eCommerce store? I’m a one-person brand with a blog who sells higher-priced online courses and the occasional ebook. So most emails are links to recently-published blog posts (where further conversion activities take place), not specials or sales, etc. on products. It’s a very long-term marketing strategy.

If my brand is all about long-form content, and a subscriber doesn’t click on a single link to read more about it in six months… when does the risk of them marking me as spam rise? … when do they start to hurt the deliverability of my entire list in the eyes of email providers… all of those “old” reasons for pruning?

I know you didn’t study this specifically, but any extrapolated thoughts in light of your analysis would be appreciated.

FYI, my products are not sold through a store plugin, just purchase buttons, and therefore I can’t connect anything to MailChimp.

Hey Scott,
Unfortunately, I do not have any real insight into what you should expect from inactive subscribers in that scenario. We are considering additional research on the topic of inactive subscribers, and we will keep your question in mind.

I have felt this is true for a long time, even without the data to back it up, and I have always resisted attempts to “clean” our list. Does this mean that Mailchimp will be revising it’s list rating/star mechanism, since this data suggested that a list has value/quality, even if the open rates (and particularly clicks) are low?

Interesting discussion, a couple of thoughts to add. Inactive subscribers who have never engaged vs inactive subscribers who have engaged at some point in the past are probably different.

For the inactive subscribers who have been customers, looking at what products they purchase vs active subscribers is useful. You may find that your content is not covering what inactive subscribers are interested well.

1. “On average, 61% of retailers’ recipients in 2015 were active” means
a. MailChimp has N retailers, i-th retailer has AR%(2015,i) active recipients percentage. And 61% is average of AR%(2015,i) for i=1..N
b. AR%(2015,i) = [Number of active recipients from Jul 1 to Dec 31, 2015] / [Number of active recipients + Number of inactive recipients + Number of purchasers who were not on the mailing list from Jan 1 to Dec 31, 2015]

Am I correct in the definitions?

2. I am not sure if lumping all users by their type (active subscribers, inactive subscribers, non-subscribers) is the best way of looking at the data. Do you have enough data to do a cohort analysis for each retailer on a month-by-month basis? I would be especially interested to look at Non-subscribers cohorts over time

Hey Aleksei,
Your first definition is correct. We calculated the percentage of recipients that were active for each business and averaged the business-level values. However, the percentage was only calculated using recipients. Non-subscribed purchasers were not included in the denominator.

We chose our methodology for a couple of reasons. The first was to produce results that are easy for readers to understand. The second was to produce a result that could easily be normalized for a single retailer and then aggregated across all of the retailers in the study. We will consider more advanced analyses like cohort analysis in the future.

Did you segment a group of people who were classified as inactive and stop sending to them? That would be a better way to measure if the inactives are reminded of you based on your emails…or simply would prefer to continue to purchase from you for other reason.

Hey Steven,
That would be a great experiment. For our analysis, we analyzed a large number of MailChimp’s customers and their lists. As such, we didn’t have the ability to perform a more controlled experiment like that. If you decide to try that out, we would love to hear the results.